/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.db.mpp.execution.schedule;

import org.apache.iotdb.db.mpp.execution.schedule.queue.IndexedBlockingQueue;
import org.apache.iotdb.db.mpp.execution.schedule.task.DriverTask;
import org.apache.iotdb.db.utils.SetThreadName;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Closeable;
import java.io.IOException;
import java.util.concurrent.ExecutionException;

/**
 * an abstract executor for {@link DriverTask}
 */
public abstract class AbstractDriverThread extends Thread implements Closeable {

    private static final Logger logger = LoggerFactory.getLogger(AbstractDriverThread.class);
    private final IndexedBlockingQueue<DriverTask> queue;
    private final ThreadProducer producer;
    protected final ITaskScheduler scheduler;
    private volatile boolean closed;

    public AbstractDriverThread(
            String workerId,
            ThreadGroup tg,
            IndexedBlockingQueue<DriverTask> queue,
            ITaskScheduler scheduler,
            ThreadProducer producer) {
        super(tg, workerId);
        this.queue = queue;
        this.scheduler = scheduler;
        this.closed = false;
        this.producer = producer;
    }

    @Override
    public void run() {
        DriverTask next;
        try {
            while (!closed && !Thread.currentThread().isInterrupted()) {
                try {
                    next = queue.poll();
                } catch (InterruptedException e) {
                    logger.warn("Executor " + this.getName() + " failed to poll driver task from queue");
                    Thread.currentThread().interrupt();
                    break;
                }

                if (next == null) {
                    logger.error("DriverTask should never be null");
                    continue;
                }

                try (SetThreadName fragmentInstanceName =
                             new SetThreadName(next.getFragmentInstance().getInfo().getFullId())) {
                    execute(next);
                } catch (Throwable t) {
                    // try-with-resource syntax will call close once after try block is done, so we need to
                    // reset the thread name here
                    try (SetThreadName fragmentInstanceName =
                                 new SetThreadName(next.getFragmentInstance().getInfo().getFullId())) {
                        logger.warn("[ExecuteFailed]", t);
                        next.setAbortCause(FragmentInstanceAbortedException.BY_INTERNAL_ERROR_SCHEDULED);
                        scheduler.toAborted(next);
                    }
                }
            }
        } finally {
            // unless we have been closed, we need to replace this thread
            if (!closed) {
                logger.warn(
                        "Executor "
                                + this.getName()
                                + " exits because it's interrupted, and we will produce another thread to replace.");
                producer.produce(getName(), getThreadGroup(), queue, producer);
            } else {
                logger.info("Executor " + this.getName() + " exits because it is closed.");
            }
        }
    }

    /**
     * Processing a task.
     */
    protected abstract void execute(DriverTask task) throws InterruptedException, ExecutionException;

    @Override
    public void close() throws IOException {
        closed = true;
    }
}
